How do you include static html files in your templates?

Hi folks,

I want to create my first html template for themes forest. But how do you create your templates without redudant html code like for the header or the footer? In PHP you can use the include function, but this is a server side include and frames are the wrong way.

How do the pros manage their static html templates? Do they use HAML to precompile the html code? Or do they really manage every single html file manually?

Thanks,
rjgamer